Commit eabe518d authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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bpf: enforce precision of R0 on program/async callback return 



Given we enforce a valid range for program and async callback return
value, we must mark R0 as precise to avoid incorrect state pruning.

Fixes: b5dc0163 ("bpf: precise scalar_value tracking")
Acked-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-9-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 0ef24c8d

kernel/bpf/verifier.c

+4 −0
Original line number Diff line number Diff line
@@ -15138,6 +15138,10 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char 
		return -EINVAL;

	}









	err = mark_chain_precision(env, regno);









	if (err)









		return err;

















	if (!retval_range_within(range, reg)) {









		verbose_invalid_scalar(env, reg, range, exit_ctx, reg_name);









		if (!is_subprog &&